text: import sys
  
  n, a, b, *x = map(int, sys.stdin.read().split())
  
  
  def main():
      border = (b + a - 1) // a
  
      res = 0
      for i in range(n - 1):
          d = x[i + 1] - x[i]
          if d >= border:
              res += b
          else:
              res += a * d
  
      return res
  
  
  if __name__ == "__main__":
      ans = main()
      print(ans)
  